class Rectangle:
    length = 0
    width = 0

    # 构造函数
    def __init__(self, length, width):
        self.length = length
        self.width = width

    def area(self):
        mianji = self.length * self.width
        print('面积：', mianji)


rectangle1 = Rectangle(5, 6)
rectangle1.area()

rectangle2 = Rectangle(3, 7)
rectangle2.area()
